


Third Wheel

by Amelia_Clark



Series: 30 Day Cheesy Trope Challenge [20]
Category: Supernatural
Genre: Anal Sex, Bodyswap, Bottom Castiel, Bottom Dean, Curious Castiel, Hilarity Ensues, M/M, Poor Sam, Top Castiel, Top Dean, magical kink
Language: English
Status: Completed
Published: 2014-12-05
Updated: 2014-12-07
Packaged: 2018-02-28 07:35:37
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,144
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2724050
Author URL: https://archiveofourown.org/users/Amelia_Clark/pseuds/Amelia_Clark
Summary: <blockquote class="userstuff">
              <p><i>Cas laid next to Dean, ran gentle fingers up his spine. "I wish I knew what that was like for you," he said.</i><br/>In which our boys try out a magical kink, and learn a valuable lesson about why they shouldn't do sex spells in common areas of the bunker. Sam is not pleased (and five inches shorter).</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> **#27: Body swap**

"Yeah, that's it," Dean groaned as Cas slid into him slowly, his breath hot on the back of Dean's neck.

"Mmm, yes." Cas held still to let Dean adjust, nipped at his shoulder, the edge of his jaw. "This feels good?" he whispered.

"God, yeah," said Dean. "No, sorry, didn't mean to mention your dad, I know we've been over this."

"It's fine. Can I move?"

"Please." Dean braced his arms more firmly on the bed as Cas pulled out a little, pushed his hips back to meet him when he thrust forward again. "Fuck, I like that," he said. "Don't stop."

Cas gasped something that wasn't a word—at least not in English—and kept thrusting, shallow but steady; he curled over Dean further, one hand slipping to grip Dean's wrist, one spread over his stomach. Dean cranked his head around for a kiss, until his neck started to hurt, and then he dropped his forehead to the mattress, elbows bending as he shifted his knees further apart.

Pushing deeper, Cas murmured Dean's name, moved his hand to circle Dean's cock. Dean was talking, but he had no idea what he was saying: just the breathy nothings of sex talk, the _yeses_ and the _mores_ and the _Castiel, baby, fuck me._ He used to be a pretty quiet lay, he thought; but their first time Cas kept asking questions _(Do you like that, am I doing this right, do you want more),_ and Dean had to answer _(yeah, yeah, please),_ and now he can't shut up.

Especially when he came—a shout, a shudder, an arch of his back. Cas's sticky hand grabbed his hip, and Dean must have asked him to fuck him harder because damn, this was some good hard fucking. He said as much, and Cas whimpered and buried himself full length, letting out a groan when he let go.

They slumped forward, rested until Dean said, "Okay, need to breathe now," and Cas pulled out, tied off the condom and tossed it in the general direction of the wastebasket. He laid next to Dean, ran gentle fingers up his spine.

"I wish I knew what that was like for you," Cas said.

"What, bottoming? Uh, you do. You like it, right?"

"I do, of course I do," Cas assured him. "That's not quite what I mean. I wish I knew what it felt like for _you,_ Dean, not for me—you're different, your body reacts differently from mine, and I find myself wishing I could experience our lovemaking from your side of it."

"Huh," Dean said after a moment. "That's not something I ever thought about. You wanna, like, possess me? I guess I'd say yes."

"I'm not sure you know what you're offering, Dean. I don't know how you'd react to being my vessel. But it would be pointless, anyway, because"—he frowned down at himself—"there's no one else in here anymore, Dean. If I were to leave this body, it would be merely a shell. We couldn't really have sex like that."

"Uh, no. That sounds really fucking disturbing." Dean shook off the thought of an empty Cas (an image that had appeared in more than one nightmare) and pondered. He wanted to give Cas everything he wanted, especially in bed, and this was—well, obviously kinda fucked up. But Cas was an angel, had been at least, whatever he was now, and Dean tried to put himself in Cas's place. To Cas, the idea must sound more kinky than creepy. And Cas had been very accommodating of Dean's kinks (foreign language, satin panties, wrists lashed to the headboard), so Dean was willing to consider this. How, though?

"Hey," Dean said after a moment, "did I ever tell you about that time back in apocalypse days this teenage nerd body-swapped with Sam?" Cas frowned and shook his head.

"Yeah, other fish to fry, I know. But this kid, he was a wannabe warlock, deep into the satanic shit, and well, he _Freaky Fridayed_ Sam against his will. So, what I mean is, obviously no demon deals, but there's at least one spell that exists to, you know, do what you wanted." Words failing him, he flapped his hand between them, hoping Cas would get it.

He did. "You would do that?" asked Cas, startled. "Let me take you over? Dean, that's," he swallowed, "that's very sweet of you."

"Well. Thanks. I mean," he gestured again, "I'd get to take that hot ass for a spin, doesn't sound like the worst thing in the world."

"Thank you," said Cas, rolling over to give Dean a better view of said ass. 

Dean gave it a firm squeeze. "Okay, so, put some clothes on and go research. Fingers crossed Sam's not in the library."


	2. Chapter 2

**Notes for the Chapter:**

> A million million thanks to lrthreads for making this 75% less confusing. (It's still a little confusing, but c'mon, it would be.)

The spell they found in the Sam-less library was pretty straightforward, though a little Lisa Frank for Dean's taste: besides frankincense and a chunk of amber, they needed a butterfly's cocoon. There were the usual flames and incantations, but it had to be cast as the butterfly emerged, so as to harness the power of its metamorphosis.

Dean sighed with relief when Cas told him they didn't have to kill the butterfly, and was immediately embarrassed. "Way to sound like a tween girl," he muttered to himself, ducking his head.

Cas tilted Dean’s chin up with one finger and gave him a smile right out of a rom-com. "I like butterflies too," he said. "They're like flying flowers. And I can ask the bees where to find them, if you can assemble the rest of the ingredients."

“Sure. I know there’s a spell cabinet around here somewhere, Sam was going on about alphabetizing it.”

When Cas returned, cradling the case of a monarch with reverent hands, Dean had everything else set up on the library table: sigils drawn, amber arranged, incense smoldering. Cas laid the cocoon down gently and passed his hand over it, as if calling to the creature inside. They joined hands, recited the Latin, and as the butterfly crawled forth, pedaling its little legs in the air—

Sam came in, carrying a stack of books. "Hey, guys, it smells like church in here."

A flash of light. Its wings spelled dry, the monarch flew away, searching for a way out into the world.

And Dean found himself with an armful of books, looking across the table at himself—and at Cas.

"What the fuck?" said Cas, and his inflection told Dean something had gone horribly wrong. This was confirmed when Cas's features took on Sam's signature disapproving bunny face.

Dean ran a hand through suddenly long hair, and said in Sam's voice, "Uh, it wasn't supposed to go like this."

Dean’s own narrowed eyes looked back at him as Cas said, "No, Sam’s entrance seems to have disrupted the spell.”

"Yeah, no shit!" Sam (Cas) yelled, stretching himself vainly towards his usual height. "Why the fuck am I in Cas's body? What the hell were you guys even trying to _do?"_

"We were planning to switch bodies and have intercourse," said Cas (Dean), because of course he did.

"NOPE." Sam grabbed the books out of Dean's hands, glaring up at him. "Of all the things I never wanted to know about— _quit staring at him with my eyes like that,"_ he hissed at Dean.

"I wasn't!" Dean protested, except he had been. He knew he was attractive and all—his looks had gotten him out of some bad situations (and into some really good ones). Something about the way Cas wore his body, though, shoulders straighter, head held higher: well, Dean was a kinkier bastard than he'd thought, because he wanted to fuck himself right goddamn now.

Except holy shit, he was getting a boner with what was supposed to be Sam's dick. "Okay," he said loudly, trying to concentrate on anything else but the most inappropriate erection in the history of sex. "We can fix this, Sammy, it's fine."

"Yes," Cas said, "I can go get another butterfly, and then we'll simply swap you and Dean."

"And I get to live with the knowledge that you're having freaky magical sex. I hate you both," said Sam.

So Dean spent an uncomfortable hour half-watching _Game of Thrones_ with a furious Sam, and doing his damnedest not to look at him, because that frown was making him look like Cas in Badass of the Lord days and that, too, was way too fucking hot for comfort.

But the spell was successful the second time; Dean felt a little disoriented suddenly shrinking five inches, but Sam's expressions were back on the right face, and he stalked off towards the garage "to go get myself good and drunk. Have fun, assholes."

Dean tugged at the lapels of the trenchcoat he now wore and glanced over at Cas, who looked back at him with the smolder that had melted the panties of many a truck stop waitress. "I'm the worst brother in the world," Dean said.

Cas cocked an eyebrow. "Lucifer," he said.

"Touché." Dean borrowed Cas's head tilt and smirked at him. "You wanna go to bed, tiger?"

And then they were in their room. His own mouth was kissing him, his own hands unbuttoning his shirt, and Dean knew this should feel weird or wrong, but it didn't. Because it was still _Cas_ touching him, rough and eager. And Dean was responding with Cas's mouth, Cas's hands; Cas's gorgeous cock was stirring in his pants, and he groaned aloud as Cas took hold of it.

"So this is how fast I make you hard, huh?" Dean gasped, pushing into the pressure.

"How do you feel?" Cas asked. "Your body wants this so much, Dean, it makes me dizzy."

 _"You_ make me dizzy, baby," said Dean, pulling off the Zeppelin shirt he’d put on this morning, past being embarrassed to ogle his own body. He reached out to trace the anti-possession tattoo, the way Cas did to him every time. "The way you touch me, feels so damn good."

"I can feel your arousal on the molecular level," purred Cas. "All of you wants you."

Dean tried to parse that sentence, shook his head. "Let's stop talking," Dean said, and pushed Cas down onto the bed.

There were certain advantages to this, Dean realized as he got Cas out of the rest of his clothes; Cas knew his body as well as another person could, but Dean was an expert. He knew how sensitive his nipples were, how good it felt to have them sucked and bitten. So he did just that, and Cas moaned so loud and low Dean knew he'd be hoarse once they switched back.

Cas used some of his own expertise to jack Dean, his grip perfect—too perfect, he felt too close in a matter of minutes. "You better stop if you wanna get fucked, Cas," he gasped. "That's what you want, right?"

"Yes," said Cas, "Dean, yes," and Dean lubed up Cas’s fingers to prod at his own ass.

“I wanna help,” said Cas, and when Dean nodded Cas reached down to join him; little by little, fingers from both their hands pushed inside. Dean was shocked by the physical reactions he felt—when he was himself, prepping Cas was a necessity, not unpleasant but not exactly a turn-on. As Cas, though? The pleasure he was giving came back to him, driving his excitement higher; whether it was angel aftereffects or just different wiring, Dean couldn’t tell, but damn. No wonder Cas preferred to top. 

With that thought, he pulled on a condom and knelt between his own thighs, lined up to enter. "Dean, my God," Cas said with Dean's voice.

"I thought we were keeping your father out of this," Dean panted as he slid in a little further.

"In vain, yes," said Cas. "But if anything deserves divine praise, it's how I feel right now."

"You feel so good, Cas," Dean said, and he didn't know if he meant right now or when their positions were switched, and it didn't matter. Any way you sliced it, he and Cas were good together.

Since Dean knew he loved being fucked hard, he tried to give Cas the same experience, and oh, Cas's body also loved it, too late to hold back. Dean had Cas's orgasm, Cas had Dean's in turn, a feedback loop of bliss that blacked out Dean’s vision for a second.

Neither of them could move or speak for two full minutes.

Then Cas shifted beneath Dean, pulled him back down for a quick kiss. "I'm guessing you liked that," he said.

Dean rolled off, still a little breathless. "I did. You got any other angel kinks I should know about?"

Cas let a mischievous grin creep across Dean's face. "How do you feel about wings?"


End file.
